Objective  To investigate the expression of microRNA-302c (miR-302c) in lung cancer, assess its influence on the invasion and migration of lung cancer, and examine the underlying mechanism.

  Methods  miR-302c expression in two lung cancer datasets (GSE19945 and GSE136043) retrieved from the online database GEO was statistically analyzed, and CREB1 expression was screened using the Human Protein Atlas. A dual luciferase assay was used to assess interactions between miR-302c and CREB1. Normal cells were cultured without any drugs; these controls were transfected with miR-302c-mimic-NC. Experimental cells were transfected with miR-302c-mimic. A transwell chamber assay was used to assess the invasion and migration ability; a tubule formation experiment was used to detect the angiogenesis ability. Western blot was used to measure the expression levels of CREB1, p-P53, and p-P21.

  Results  Online bioinformatics analyses showed that, compared with normal tissues, miR-302c expression was significantly reduced in lung cancer tissue and lung cancer lymphatic metastasis tissue, and CREB1 expression in lung cancer tissue was significantly increased. Dual luciferase assays showed that miR-302c regulated CREB1 expression; compared with the controls, the number of cells that migrated and invaded and the number of tubules were significantly decreased in the treatment group, CREB1 was significantly decreased in treated cells, and expression of p-P53 and p-P21 was increased (P<0.05, each).

  Conclusions  miR-302c expression in lung cancer tissue is reduced. Overexpression of miR-302c can significantly inhibit the invasion and metastasis of lung cancer cells, which may be related to reduced CREB1 expression and activation of the P53 signaling pathway.